Webster County public health officials are seeking the source of a parasite that has made 13 people sick over the last two weeks.
Kari Prescott, the executive director of the Webster County Health Department, said there has been an outbreak of cryptosporidiosis, a condition caused by a microscopic parasite that leads to diarrhea.
''There's lots of things we need to investigate before we can legitimately say where the parasite is coming from,'' Prescott said.
The disease is caused by the cryptosporidium parasite. It is different from cyclospora, which caused a highly publicized outbreak in several states earlier this summer.
Thirteen illnesses in a county with a population of nearly 40,000 people would appear to be a small number, but it is a large enough number to warrant the attention of public health officials, according to Prescott. She said there are usually just one or two cryptosporidiosis cases at a time.
The disease is contracted by ingesting water or food that is contaminated with the feces of an already infected person or animal, according to the Iowa Department of Public Health.
Prescott said public health officials are interviewing those who have been ill to ''try to find a common spot where people might have ingested this parasite.''
She said people can usually recover from cryptosporidiosis without help. She said medicines may be prescribed in some cases. She added that none of the people who recently became ill had to be hospitalized.
The splash pad at Oleson Park was shut down early on Monday so that the staff could ''super chlorinate'' it as a preventive measure, said Ryan Maehl, the city's recreation administrator. He said the chlorine level in the site's water was increased to very high levels to kill any cryptosporidium that may have been there. The splash pad reopened at 9 a.m. Tuesday.
''We were being very proactive,'' Maehl said. ''We want to provide a fun and safe environment for people to have fun and cool off in.''